Adapted from Hersheys.com
2 cups sugar
cup (1 1/2 sticks) butter or margarine
1 1/2 teaspoons vanilla extract
Preheat oven to 350°. Grease and flour three 9-inch round cake pans. Line bottoms with parchment rounds, and grease parchment. Set aside.
Stir together sugar, flour, cocoa, baking powder, baking soda and salt in a large bowl. Add eggs, buttermilk, oil and vanilla; with a mixer, beat on medium speed for about 2 minutes. Carefully, stir in hot coffee. The batter will be very thin. Pour batter into prepared cake pans. (Use kitchen scale for even division if desired).
Bake for 20-23 minutes or until a toothpick inserted in center comes out clean. Cool 10 minutes; remove from pans to wire racks. Cool completely. Frost with chocolate frosting.
To make frosting, melt butter. Stir in cocoa. Alternately add powdered sugar and milk, beating to spreading consistency.
Add small amount additional milk, if needed. Stir in vanilla. Makes about 3 cups frosting.